Graphene-Based Materials for Biosensors: A Review

Generating luminescent Graphene quantum Dots from Tryptophan: Fluorosensors for hydrogen peroxide in cancer cells

Herein, we report a single step synthesis of highly fluorescent Graphene Quantum Dots (GQDs) using tryptophan and glycerol as precursors via pyrolysis. The morphological and functional characterization of the prepared GQDs was performed using PXRD, FTIR, TEM, XPS and zeta potential measurements. The prepared GQDs found their practical application in ultrasensitive detection of an emerging potential cancer biomarker, H2O2, by exploiting the fluorescence quenching behaviour of H2O2. To evaluate the detection sensitivity, a series of various concentrations of H2O2 was spiked to biomatrices like, serum and MCF-7 (human breast cancer cell line) cell lysate medium. A remarkably low limit of detection (LOD) was found in serum medium (139.5 pM) which further improved in MCF-7 cell lysate medium (LOD 61.43 pM). Moreover, the sensing capacity of the GQDs was further validated in presence of various physiological variables such as glucose, cholesterol, insulin and nitrite. Sensing assay was also carried out in HaCaT (human keratinocyte cell line) cell lysate medium to compare the performance of our prepared sensor but the non-linearity of the F0/F versus H2O2 concentration plot pointed towards the conduciveness of the MCF-7 cell lysate medium for sensitive detection of H2O2.The mechanism behind the sensing was also explored using spectroscopic methods.

Biosensors with left ventricular assist devices

Heart failure imposes a significant global health burden, standing as a primary contributor to mortality. Various indicators and physiological shifts within the body may hint at distinct cardiac conditions. Specific biosensors have the capability to identify these changes. Integrating or embedding these biosensors into mechanical circulatory support devices (MCSDs), such as left ventricular assist devices (LVADs), becomes crucial for monitoring alterations in biochemical and physiological factors subsequent to an MCSD implantation. Detecting abnormal changes early in the course of disease progression will allow for improved patient outcomes and prognosis following an MCSD implantation. The aim of this review is to explore the available biosensors that may be coupled or implanted alongside LVADs to monitor biomarkers and changes in physiological parameters. Different fabrication materials for the biosensors are discussed, including their advantages and disadvantages. This review also examines the feasibility of integrating feedback control mechanisms into LVAD systems using data from the biosensors. Challenges facing this emerging technology and future directions for research and development are outlined as well. The overarching goal is to provide an overview of how implanted biosensors may improve the performance and outcomes of LVADs through continuous monitoring and closed-loop control.

Graphene-Based Photodynamic Therapy and Overcoming Cancer Resistance Mechanisms: A Comprehensive Review

Photodynamic therapy (PDT) is a non-invasive therapy that has made significant progress in treating different diseases, including cancer, by utilizing new nanotechnology products such as graphene and its derivatives. Graphene-based materials have large surface area and photothermal effects thereby making them suitable candidates for PDT or photo-active drug carriers. The remarkable photophysical properties of graphene derivates facilitate the efficient generation of reactive oxygen species (ROS) upon light irradiation, which destroys cancer cells. Surface functionalization of graphene and its materials can also enhance their biocompatibility and anticancer activity. The paper delves into the distinct roles played by graphene-based materials in PDT such as photosensitizers (PS) and drug carriers while at the same time considers how these materials could be used to circumvent cancer resistance. This will provide readers with an extensive discussion of various pathways contributing to PDT inefficiency. Consequently, this comprehensive review underscores the vital roles that graphene and its derivatives may play in emerging PDT strategies for cancer treatment and other medical purposes. With a better comprehension of the current state of research and the existing challenges, the integration of graphene-based materials in PDT holds great promise for developing targeted, effective, and personalized cancer treatments.

Microbial Biofilms: Features of Formation and Potential for Use in Bioelectrochemical Devices

Microbial biofilms present one of the most widespread forms of life on Earth. The formation of microbial communities on various surfaces presents a major challenge in a variety of fields, including medicine, the food industry, shipping, etc. At the same time, this process can also be used for the benefit of humans-in bioremediation, wastewater treatment, and various biotechnological processes. The main direction of using electroactive microbial biofilms is their incorporation into the composition of biosensor and biofuel cells This review examines the fundamental knowledge acquired about the structure and formation of biofilms, the properties they have when used in bioelectrochemical devices, and the characteristics of the formation of these structures on different surfaces. Special attention is given to the potential of applying the latest advances in genetic engineering in order to improve the performance of microbial biofilm-based devices and to regulate the processes that take place within them. Finally, we highlight possible ways of dealing with the drawbacks of using biofilms in the creation of highly efficient biosensors and biofuel cells.

Biosensors for metastatic cancer cell detection

Early detection and effective cancer treatment are critical to improving metastatic cancer cell diagnosis and management today. In particular, accurate qualitative diagnosis of metastatic cancer cell represents an important step in the diagnosis of cancer. Today, biosensors have been widely developed due to the daily need to measure different chemical and biological species. Biosensors are utilized to quantify chemical and biological phenomena by generating signals that are directly proportional to the quantity of the analyte present in the reaction. Biosensors are widely used in disease control, drug delivery, infection detection, detection of pathogenic microorganisms, and markers that indicate a specific disease in the body. These devices have been especially popular in the field of metastatic cancer cell diagnosis and treatment due to their portability, high sensitivity, high specificity, ease of use and short response time. This article examines biosensors for metastatic cancer cells. It also studies metastatic cancer cells and the mechanism of metastasis. Finally, the function of biosensors and biomarkers in metastatic cancer cells is investigated.

Graphene-based biosensors in milk analysis: A review of recent developments

Cow's milk, an excellent source of fat, protein, amino acids, vitamins and minerals, is currently one of the most consumed products worldwide. Contaminations originating from diverse sources, such as biological, chemical, and physical, cause dairy product quality problems and thus dairy-related disorders, raising public health issues. For this reason, legal authorities have deemed it necessary to classify certain contaminations in commercial milk and keep them within particular limitations; therefore, it is urgent to develop next-generation detection systems that can accurately identify just the contaminants of concern to human health. This review presents a detailed investigation of biosensors based on graphene and its derivatives, which offer superior sensitivity and selectivity, by classifying the contaminants under the headings biological, chemical, and physical, in cow's milk according to their sources. We reviewed the current status of graphene-based biosensor (GBs) technology for milk or dairy analysis, highlighting its strengths and weaknesses with the help of comparative studies, tables, and charts, and we put forward a novel perspective to handle future challenges.

Fentogram electrochemical detection of HIV RNA based on graphene quantum dots and gold nanoparticles

This work reports the construction of an HIV-specific genosensor through the modification of carbon screen-printed electrodes (CSPE) with graphene quantum dots decorated with L-cysteine and gold nanoparticles (cys-GQDs/AuNps). Cys-GQDs were characterized by FT-IR and UV-vis spectra and electronic properties of the modified electrodes were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The modification of the electrode surface with cys-GQDs and AuNps increased the electrochemical performance of the electrode, improving the electron transfer of the anionic redox probe [Fe(CN)6]3-/4- on the electrochemical platform. When compared to the bare surface, the modified electrode showed a 1.7 times increase in effective electrode area and a 29 times decrease in charge transfer resistance. The genosensor response was performed by differential pulse voltammetry, monitoring the current response of the anionic redox probe, confirmed with real genomic RNA samples, making it possible to detect 1 fg/mL. In addition, the genosensor maintained its response for 60 days at room temperature. This new genosensor platform for early detection of HIV, based on the modification of the electrode surface with cys-GQDs and AuNps, discriminates between HIV-negative and positive samples, showing a low detection limit, as well as good specificity and stability, which are relevant properties for commercial application of biosensors.

Graphene-based materials as nanoplatforms for antiviral therapy and prophylaxis

INTRODUCTION

The dramatic effects caused by viral diseases have prompted the search for effective therapeutic and preventive agents. In this context, 2D graphene-based nanomaterials (GBNs) have shown great potential for antiviral therapy, enabling the functionalization and/or decoration with biomolecules, metals and polymers, able to improve their interaction with viral nanoparticles.

AREAS COVERED

This review summarizes the most recent advances of the antiviral research related to 2D GBNs, based on their antiviral mechanism of action. Their ability to inactivate viruses by inhibiting the entry inside cells, or through drug/gene delivery, or by stimulating the host immune response are here discussed. As reported, biological studies performed in vitro and/or in vivo allowed to demonstrate the antiviral activity of the developed GBNs, at different stages of the virus life cycle and the evaluation of their long-term toxicity. Other mechanisms closely related to the physicochemical properties of GBNs are also reported, demonstrating the potential of these materials for antiviral prophylaxis.

EXPERT OPINION

GBNs represent valuable tools to fight emerging or reemerging viral infections. However, their translation into the clinic requires standardized scale-up procedures leading to the reliable and reproducible synthesis of these nanomaterials with suitable physicochemical properties, as well as more in-depth pharmacological and toxicological investigations. We believe that multidisciplinary approaches will give valuable solutions to overcome the encountered limitations in the application of GBNs in biomedical and clinical field.

Radiolabeled florescent-magnetic graphene oxide nanosheets: probing the biodistribution of a potential PET-MRI hybrid imaging agent for detection of fibrosarcoma tumor

PURPOSE

Radiolabeled graphene oxide (GO) nanosheets has been one of the most extensively studied nanoplatform for in vivo radioisotope delivery. Herein, we describe the functionalization of the surface of GO nanosheets with Fe3O4 magnetic nanoparticles, cysteine amino acid as an interface ligand, and cadmium telluride quantum dots.

MATERIALS AND METHODS

To enable In vivo PET imaging, the GO@Fe3O4-cys-CdTe QDs were labeled with 68Ga to yield [68Ga] Ga-Go@ Fe3O4-Cys-CdTe QDs. Furthermore, serum stability tests were performed and the biological behavior of the nanocomposite was evaluated in rats bearing fibrosarcoma tumor.

RESULTS

Liver, blood and tumor were the most accumulated sites at 1 h after the injection, and the radiolabeled nanocomposite as a PET/MRI imaging agent showed fast depletion from body and acceptable tumor uptake.

CONCLUSION

Magnetic (Fe3O4) and fluorescent components (CdTe QDs) along with a positron-emitting radionuclide will help to design a multimodal imaging system (PET/MRI/OI) which will offer the advantages of combined imaging techniques and further possible used in localized radionuclide therapy. Overall, [68Ga] Ga-GO@Fe3O4-cys-CdTe QDs nanocomposite shows great promise as a radiolabeled imaging agent owing to high accumulation in tumor region.

Flower like-novel nanocomposite of Mg(Ti0.99Sn0.01)O3decorated on reduced graphene oxide (rGO) with high capacitive behavior as supercapacitor electrodes

In this study, ceramic materials of Mg(Ti0.99Sn0.01)O3were synthesized and decorated on reduced graphene oxide, forming a nanocomposite of rGO/Mg(Ti0.99Sn0.01)O3(rGO/MTS001). The successful synthesis results were confirmed by XRD, UV-vis analysis, FT-IR, and SEM-EDS. The MTS001 has a flower-like morphology from scanning electron microscopy (SEM) analysis, and the nanocomposites of rGO/MTS001 showed MTS001 particles decorated on the rGO's surface. The electrochemical performance of rGO/MTS001 and MTS001 was investigated by determining the specific capacitance obtained in 1 M H2SO4solution by cyclic voltammetry, followed by galvanostatic charge-discharge analysis using a three-electrode setup. The rGO/MTS001 achieved a specific capacitance of 361.97 F g‒1, compared to MTS001 (194.90 F g‒1). The capacitance retention of rGO/MTS001 nanocomposite also depicted excellent cyclic stability of 95.72% after 5000 cycles at a current density of 0.1 A g‒1. The result showed that the nanocomposite of ceramics with graphene materials has a potential for high-performance supercapacitor electrodes.

Interplay of graphene-DNA interactions: Unveiling sensing potential of graphene materials

Graphene-based materials and DNA probes/nanostructures have emerged as building blocks for constructing powerful biosensors. Graphene-based materials possess exceptional properties, including two-dimensional atomically flat basal planes for biomolecule binding. DNA probes serve as excellent selective probes, exhibiting specific recognition capabilities toward diverse target analytes. Meanwhile, DNA nanostructures function as placement scaffolds, enabling the precise organization of molecular species at nanoscale and the positioning of complex biomolecular assays. The interplay of DNA probes/nanostructures and graphene-based materials has fostered the creation of intricate hybrid materials with user-defined architectures. This advancement has resulted in significant progress in developing novel biosensors for detecting DNA, RNA, small molecules, and proteins, as well as for DNA sequencing. Consequently, a profound understanding of the interactions between DNA and graphene-based materials is key to developing these biological devices. In this review, we systematically discussed the current comprehension of the interaction between DNA probes and graphene-based materials, and elucidated the latest advancements in DNA probe-graphene-based biosensors. Additionally, we concisely summarized recent research endeavors involving the deposition of DNA nanostructures on graphene-based materials and explored imminent biosensing applications by seamlessly integrating DNA nanostructures with graphene-based materials. Finally, we delineated the primary challenges and provided prospective insights into this rapidly developing field. We envision that this review will aid researchers in understanding the interactions between DNA and graphene-based materials, gaining deeper insight into the biosensing mechanisms of DNA-graphene-based biosensors, and designing novel biosensors for desired applications.

Graphene-Based Nanomaterials and Their Interactions with Lipid Membranes

Graphene-based nanomaterials (GNMs) have captured increasing attention in the recent advancement of materials science and nanotechnology owing to their excellent physicochemical properties. Despite having unquestionable advances, the application of GNMs in biological and medical sciences is still limited due to the lack of knowledge and precise control over their interaction with the biological milieu. The cellular membrane is the first barrier with which GNMs interact before entering a cell. Therefore, understanding how they interact with cell membranes is important from the perspective of safe use in biological and biomedical fields. In this review, we systematically summarize the recent efforts in predicting the interactions between GNMs and model cellular membranes. This review provides insights into how GNMs interact with lipid membranes and self-assemble in and around them. Both the computational simulations and experimental observations are summarized. The interactions are classified depending on the physicochemical properties (structure, chemistry, and orientation) of GNMs and various model membranes. The thermodynamic parameters, structural details, and supramolecular forces are listed to understand the interactions which would help circumvent potential risks and provide guidance for safe use in the future. At the end of this review, future prospective and emerging challenges in this research field are discussed.

Nanosensor Chemical Cytometry: Advances and Opportunities in Cellular Therapy and Precision Medicine

With the definition of therapeutics now encompassing transplanted or engineered cells and their molecular products, there is a growing scientific necessity for analytics to understand this new category of drugs. This Perspective highlights the recent development of new measurement science on label-free single cell analysis, nanosensor chemical cytometry (NCC), and their potential for cellular therapeutics and precision medicine. NCC is based on microfluidics integrated with fluorescent nanosensor arrays utilizing the optical lensing effect of a single cell to real-time extract molecular properties and correlate them with physical attributes of single cells. This new class of cytometry can quantify the heterogeneity of the multivariate physicochemical attributes of the cell populations in a completely label-free and nondestructive way and, thus, suggest the vein-to-vein conditions for the safe therapeutic applications. After the introduction of the NCC technology, we suggest the technological development roadmap for the maturation of the new field: from the sensor/chip design perspective to the system/software development level based on hardware automation and deep learning data analytics. The advancement of this new single cell sensing technology is anticipated to aid rich and multivariate single cell data setting and support safe and reliable cellular therapeutics. This new measurement science can lead to data-driven personalized precision medicine.

Recent Advances of Graphene Quantum Dots in Chemiresistive Gas Sensors

Graphene quantum dots (GQDs), as 0D graphene nanomaterials, have aroused increasing interest in chemiresistive gas sensors owing to their remarkable physicochemical properties and tunable electronic structures. Research on GQDs has been booming over the past decades, and a number of excellent review articles have been provided on various other sensing principles of GQDs, such as fluorescence-based ion-sensing, bio-sensing, bio-imaging, and electrochemical, photoelectrochemical, and electrochemiluminescence sensing, and therapeutic, energy and catalysis applications. However, so far, there is no single review article on the application of GQDs in the field of chemiresistive gas sensing. This is our primary inspiration for writing this review, with a focus on the chemiresistive gas sensors reported using GQD-based composites. In this review, the various synthesized strategies of GQDs and its composites, gas sensing enhancement mechanisms, and the resulting sensing characteristics are presented. Finally, the current challenges and future prospects of GQDs in the abovementioned application filed have been discussed for the more rational design of advanced GQDs-based gas-sensing materials and innovative gas sensors with novel functionalities.

Reduced Graphene Oxide Electrolyte-Gated Transistor Immunosensor with Highly Selective Multiparametric Detection of Anti-Drug Antibodies

The advent of immunotherapies with biological drugs has revolutionized the treatment of cancers and auto-immune diseases. However, in some patients, the production of anti-drug antibodies (ADAs) hampers the drug efficacy. The concentration of ADAs is typically in the range of 1-10 pm; hence their immunodetection is challenging. ADAs toward Infliximab (IFX), a drug used to treat rheumatoid arthritis and other auto-immune diseases, are focussed. An ambipolar electrolyte-gated transistor (EGT) immunosensor is reported based on a reduced graphene oxide (rGO) channel and IFX bound to the gate electrode as the specific probe. The rGO-EGTs are easy to fabricate and exhibit low voltage operations (≤ 0.3 V), a robust response within 15 min, and ultra-high sensitivity (10 am limit of detection). A multiparametric analysis of the whole rGO-EGT transfer curves based on the type-I generalized extreme value distribution is proposed. It is demonstrated that it allows to selectively quantify ADAs also in the co-presence of its antagonist tumor necrosis factor alpha (TNF-α), the natural circulating target of IFX.

Graphene derivatives-based electrodes for the electrochemical determination of carbamate pesticides in food products: A review

Graphene (GR) composites have great potential for the determination of carbamates pesticides (CPs) by electrochemical methods. Since the beginning of the 20th century, GR has shown remarkable promise as electrode material for various sensors. The contamination of food products with harmful CPs is a major problem as they do not always damage human health immediately, but can be harmful after prolonged exposure. A range of advantages can be gained from their electrochemical determination, such as high sensitivity, reasonably selectivity, rapid detection, low limit of detection, and easy electrode fabrication. Furthermore, these electrochemical techniques are robust, reproducible, user-friendly, and conform to both "green" and "white" analytical chemistry. This review is focused on results published in the last ten years in the field of electrochemical determination of CPs in food products using GR and its derivatives.

Numerical Investigation on High-Performance Cu-Based Surface Plasmon Resonance Sensor for Biosensing Application

This numerical research presents a simple hybrid structure comprised of TiO2-Cu-BaTiO3 for a modified Kretschmann configuration that exhibits high sensitivity and high resolution for biosensing applications through an angular interrogation method. Recently, copper (Cu) emerged as an exceptional choice as a plasmonic metal for developing surface plasmon sensors (SPR) with high resolution as it yields finer, thinner SPR curves than Ag and Au. As copper is prone to oxidation, especially in ambient conditions, the proposed structure involves the utilization of barium titanate (BaTiO3) film as a protection layer that not only preserves Cu film from oxidizing but enhances the performance of the sensor to a great extent. Numerical results also show that the utilization of a thin adhesive layer of titanium dioxide (TiO2) between the prism base and Cu film not only induces strong interaction between them but also enhances the performance of the sensor. Such a configuration, upon suitable optimization of the thickness of each layer, is found to enhance sensitivity as high as 552°/RIU with a figure of merit (FOM) of 136.97 RIU-1. This suggested biosensor design with enhanced sensitivity is expected to enable long-term detection with greater accuracy and sensitivity even when using Cu as a plasmonic metal.

Graphene-Based Wearable Temperature Sensors: A Review

Flexible sensing electronics have received extensive attention for their potential applications in wearable human health monitoring and care systems. Given that the normal physiological activities of the human body are primarily based on a relatively constant body temperature, real-time monitoring of body surface temperature using temperature sensors is one of the most intuitive and effective methods to understand physical conditions. With its outstanding electrical, mechanical, and thermal properties, graphene emerges as a promising candidate for the development of flexible and wearable temperature sensors. In this review, the recent progress of graphene-based wearable temperature sensors is summarized, including material preparation, working principle, performance index, classification, and related applications. Finally, the challenges and future research emphasis in this field are put forward. This review provides important guidance for designing novel and intelligent wearable temperature-sensing systems.

Direct Ink Writing of Carbon-Doped Polymeric Composite Ink: A Review on Its Requirements and Applications

Direct Ink Writing (DIW) opens new possibilities in three-dimensional (3D) printing of carbon-based polymeric ink. This is due to its ability in design flexibility, structural complexity, and environmental sustainability. This area requires exhaustive study because of its wide application in different manufacturing sectors. The present article is related to the variant emerging 3D printing techniques and DIW of carbonaceous materials. Carbon-based materials, extensively used for various applications in 3D printing, possess impressive chemical stability, strength, and flexible nanostructure. Fine printable inks consist predominantly of uniform solutions of carbon materials, such as graphene, graphene oxide (GO), carbon fibers (CFs), carbon nanotubes (CNTs), and solvents. It also contains compatible polymers and suitable additives. This review article elaborately discusses the fundamental requirements of DIW in structuring carbon-doped polymeric inks viz. ink formulation, required ink rheology, extrusion parameters, print fidelity prediction, layer bonding examination, substrate selection, and curing method to achieve fine functional composites. A detailed description of its application in the fields of electronics, medical, and mechanical segments have also been focused in this study.

N-doped carbon nanomaterials as fluorescent pH and metal ion sensors for imaging

Herein we describe the facile synthesis of new N-doped carbon nanoparticles (CNPs) obtained from 1,10-phenanthroline by the solvothermal method. Characterization of CNPs were carried out with transmission electron microscope (TEM), X-ray photoelectron spectra (XPS), Fourier transform infrared spectra (FTIR), UV-vis absorption spectra, and luminescence spectra. CNPs were pH sensitive and exploited as fluorescent chemosensors and imaging agents for Al(III) and Zn(II) ions in real-life samples. Remarkably, we show that CNPs can be used for the detection of Al(III) and Zn(II) ions in water samples. Accordingly, the results indicate that CNPs are highly effective in detecting Zn(II) content of cosmetic creams. We also demonstrated that the CNPs could be used for in vitro imaging of Al(III) and Zn(II) in Human Larynx Squamous Cell Carcinoma (Hep-2). Finally, Al(III) imaging in Angelica Officinalis root tissue was also achieved successfully. The CNPs are promising as luminescent multianalyte (pH, Al(III) and Zn(II)) sensors.

Development of Two-Dimensional Functional Nanomaterials for Biosensor Applications: Opportunities, Challenges, and Future Prospects

New possibilities for the development of biosensors that are ready to be implemented in the field have emerged thanks to the recent progress of functional nanomaterials and the careful engineering of nanostructures. Two-dimensional (2D) nanomaterials have exceptional physical, chemical, highly anisotropic, chemically active, and mechanical capabilities due to their ultra-thin structures. The diversity of the high surface area, layered topologies, and porosity found in 2D nanomaterials makes them amenable to being engineered with surface characteristics that make it possible for targeted identification. By integrating the distinctive features of several varieties of nanostructures and employing them as scaffolds for bimolecular assemblies, biosensing platforms with improved reliability, selectivity, and sensitivity for the identification of a plethora of analytes can be developed. In this review, we compile a number of approaches to using 2D nanomaterials for biomolecule detection. Subsequently, we summarize the advantages and disadvantages of using 2D nanomaterials in biosensing. Finally, both the opportunities and the challenges that exist within this potentially fruitful subject are discussed. This review will assist readers in understanding the synthesis of 2D nanomaterials, their alteration by enzymes and composite materials, and the implementation of 2D material-based biosensors for efficient bioanalysis and disease diagnosis.

Plasmonic Sensors: A New Frontier in Nanotechnology

Plasmonics is the study of surface plasmons formed by the interaction of incident light with electrons to form a surface-bound electromagnetic wave [...].

Portable reduced graphene oxide biosensor for detection of rabies virus in bats using nasopharyngeal swab samples

Rabies is a lethal zoonotic disease caused by rabies virus (RABV) that affects human health and the economy. RABV is transmitted mainly by bats in Brazil, and surveillance in remote areas is hampered by the difficulty of properly collecting samples during fieldwork and the diagnosis is performed in laboratory conditions. Here, we report a portable electrochemical biosensor based on nucleic acid interactions for RABV detection in nasopharyngeal swab samples. The working electrode of the biosensor is composed of reduced graphene oxide (rGO) thin-film immobilized with cDNA through pi-pi stacking to enhance virus detection and specificity. Sensor performance was determined using RNA, and swab samples from bats. RNA detection shows good selectivity, and quantification presents a highly linear calibration curve (R² = 0.990) using a concentration range of 0.145-25.39 ng/μL. A LOD of 0.104 ng/μL was reached with a sensitivity of 0.321 μA (ng/μL)^-1. RABV detection in nasopharyngeal swab samples showed a good difference of positive sample from negative with a response time in seconds, ultra-fast detection compared to known techniques. Three biosensor groups were identified and named after physic-chemical surface characterization as: GO-1, GO-2, and rGO; with best performance for rGO group due to its sp² hybridized network. Thus, we have successfully fabricated a promising electrochemical biosensor for fast in-situ detection of the RABV in swab samples, which can be expanded to other enveloped viruses that have RNA.

Smart Graphene-Based Electrochemical Nanobiosensor for Clinical Diagnosis: Review

The technological improvement in the field of physics, chemistry, electronics, nanotechnology, biology, and molecular biology has contributed to the development of various electrochemical biosensors with a broad range of applications in healthcare settings, food control and monitoring, and environmental monitoring. In the past, conventional biosensors that have employed bioreceptors, such as enzymes, antibodies, Nucleic Acid (NA), etc., and used different transduction methods such as optical, thermal, electrochemical, electrical and magnetic detection, have been developed. Yet, with all the progresses made so far, these biosensors are clouded with many challenges, such as interference with undesirable compound, low sensitivity, specificity, selectivity, and longer processing time. In order to address these challenges, there is high need for developing novel, fast, highly sensitive biosensors with high accuracy and specificity. Scientists explore these gaps by incorporating nanoparticles (NPs) and nanocomposites (NCs) to enhance the desired properties. Graphene nanostructures have emerged as one of the ideal materials for biosensing technology due to their excellent dispersity, ease of functionalization, physiochemical properties, optical properties, good electrical conductivity, etc. The Integration of the Internet of Medical Things (IoMT) in the development of biosensors has the potential to improve diagnosis and treatment of diseases through early diagnosis and on time monitoring. The outcome of this comprehensive review will be useful to understand the significant role of graphene-based electrochemical biosensor integrated with Artificial Intelligence AI and IoMT for clinical diagnostics. The review is further extended to cover open research issues and future aspects of biosensing technology for diagnosis and management of clinical diseases and performance evaluation based on Linear Range (LR) and Limit of Detection (LOD) within the ranges of Micromolar µM (10^-6), Nanomolar nM (10^-9), Picomolar pM (10^-12), femtomolar fM (10^-15), and attomolar aM (10^-18).

Advanced Technologies for Potency Assay Measurement

Crucial for their application, cell products need to be well-characterized in the cell manufacturing facilities and conform to regulatory approval criteria before infusion into the patients. Mesenchymal Stromal Cells (MSCs) are the leading cell therapy candidate in clinical trials worldwide. Early phase clinical trials have demonstrated that MSCs display an excellent safety profile and are well tolerated. However, MSCs have also exhibited contradictory efficacy in later-phase clinical trials with reasons for this discrepancy including poorly understood mechanism of MSC therapeutic action. With likelihood that a number of attributes are involved in MSC derived clinical benefit, an assay that measures a single quality of may not adequately reflect potency, thus a combination of bioassays and analytical methods, collectively called "assay matrix" are favoured for defining the potency of MSC more adequately. This chapter highlights advanced technologies and targets that can achieve quantitative measurement for a range of MSC attributes, including immunological, genomic, secretome, phosphorylation, morphological, biomaterial, angiogenic and metabolic assays.

Flexible Graphene-Copper Nanocomposite for Potential Wearable Electronics Applications

The demand for flexible and wearable electrochemical sensors has surged due to their low cost and portability. This study produces and characterizes low-cost and environmentally friendly flexible laser engraved graphene/Cu nanoparticles composite materials as a potential electrode for electronic applications. The electrode is fabricated by directly engraving Polyimide substrate using a CO2 laser machine to produce Laser Engraved Graphene (LEG). The electrode is then modified with copper nanoparticles via a one-step pulse electrodeposition technique to be characterized structurally, mechanically, and electrochemically using SEM, XRD, bending test, electrochemical impedance spectroscopy, and cyclic voltammetry to assess their stability and electrocatalytic activity. The laser irradiation of PI results in 3D porous graphene structure formation that increases electron transfer rate and the electrochemically active surface area. Copper deposition improves the sensitivity of LEG by its high conductivity.

A Hemin-Graphene Nanocomposite-Based Aptasensor for Ultrasensitive Colorimetric Quantification of Leukaemia Cells Using Magnetic Enrichment

Diagnostic blood cell counting is of limited use in monitoring a minimal number of leukaemia cells, warranting further research to develop more sensitive and reliable techniques to identify leukaemia cells in circulation. In this work, a hemin-graphene nanocomposite-based aptasensor was developed for ultrasensitive colorimetric detection of leukaemia cells (CEM) using magnetic enrichment. Hemin-conjugated graphene oxide nanocomposites (HGNs) were prepared by hydrazine reduction using graphene oxide nanosheets and hemins. Hence, the prepared HGNs become able to absorb single-stranded DNA and acquire peroxidase-like activity. The aptamer sgc8c, which recognizes a specific target on leukaemia cells, was absorbed onto HGNs to capture the target CEM cancer cells. The captured target cells that associated with the HGNs were then concentrated and separated by magnetic beads (MBs) coated with sgc8c aptamers, forming a HGN-cell-MB sandwich structure. These sandwich structures can be quantified via an oxidation reaction catalysed by HGNs. By utilizing dual signal amplification effects generated by magnetic enrichment and the improved peroxidase activity of HGNs, the biosensor allowed for highly sensitive detection of 10 to 10⁵ CEM cells with an ultra-low limit of detection (LOD) of 10 cells under optimal conditions. It is expected that the proposed aptasensor can be further employed in monitoring the minimal residual disease during the treatment of leukaemia.

Antimicrobial Activity of Graphene-Based Nanocomposites: Synthesis, Characterization, and Their Applications for Human Welfare

Graphene (GN)-related nanomaterials such as graphene oxide, reduced graphene oxide, quantum dots, etc., and their composites have attracted significant interest owing to their efficient antimicrobial properties and thus newer GN-based composites are being readily developed, characterized, and explored for clinical applications by scientists worldwide. The GN offers excellent surface properties, i.e., a large surface area, pH sensitivity, and significant biocompatibility with the biological system. In recent years, GN has found applications in tissue engineering owing to its impressive stiffness, mechanical strength, electrical conductivity, and the ability to innovate in two-dimensional (2D) and three-dimensional (3D) design. It also offers a photothermic effect that potentiates the targeted killing of cells via physicochemical interactions. It is generally synthesized by physical and chemical methods and is characterized by modern and sophisticated analytical techniques such as NMR, Raman spectroscopy, electron microscopy, etc. A lot of reports show the successful conjugation of GN with existing repurposed drugs, which improves their therapeutic efficacy against many microbial infections and also its potential application in drug delivery. Thus, in this review, the antimicrobial potentialities of GN-based nanomaterials, their synthesis, and their toxicities in biological systems are discussed.

One-Step Synthesis of Aminobenzoic Acid Functionalized Graphene Oxide by Electrochemical Exfoliation of Graphite for Oxygen Reduction to Hydrogen Peroxide and Supercapacitors

Graphene-based materials have attracted considerable attention as promising electrocatalysts for the oxygen reduction reaction (ORR) and as electrode materials for supercapacitors. In this work, electrochemical exfoliation of graphite in the presence of 4-aminebenzoic acid (4-ABA) is used as a one-step method to prepare graphene oxide materials (EGO) functionalized with aminobenzoic acid (EGO-ABA). The EGO and EGO-ABAs materials were characterized by FT-IR spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction and scanning electron microscopy. It was found that the EGO-ABA materials have smaller flake size and higher density of oxygenated functional groups compared to bare EGO. The electrochemical studies showed that the EGO-ABA catalysts have higher activity for the ORR to H2O2 in alkaline medium compared to EGO due to their higher density of oxygenated functional groups. However, bare EGO has a higher selectivity for the 2-electron process (81%) compared to the EGO-ABA (between 64 and 72%) which was related to a lower content of carbonyl groups. The specific capacitance of the EGO-ABA materials was higher than that of EGO, with an increase by a factor of 3 for the materials prepared from exfoliation in 5 mM 4-ABA/0.1 M H2SO4. This electrode material also showed a remarkable cycling capability with a loss of only 19.4% after 5000 cycles at 50 mVs−1.

Semiconductor quantum dots for photodynamic therapy: Recent advances

Photodynamic therapy is a promising cancer treatment that induces apoptosis as a result of the interactions between light and a photosensitizing drug. Lately, the emergence of biocompatible nanoparticles has revolutionized the prospects of photodynamic therapy (PDT) in clinical trials. Consequently, a lot of research is now being focused on developing non-toxic, biocompatible nanoparticle-based photosensitizers for effective cancer treatments using PDT. In this regard, semiconducting quantum dots have shown encouraging results. Quantum dots are artificial semiconducting nanocrystals with distinct chemical and physical properties. Their optical properties can be fine-tuned by varying their size, which usually ranges from 1 to 10 nm. They present many advantages over conventional photosensitizers, mainly their emission properties can be manipulated within the near IR region as opposed to the visible region by the former. Consequently, low intensity light can be used to penetrate deeper tissues owing to low scattering in the near IR region. Recently, successful reports on imaging and PDT of cancer using carbon (carbon, graphene based) and metallic (Cd based) based quantum dots are promising. This review aims to summarize the development and the status quo of quantum dots for cancer treatment.

A Critical Analysis on the Sensitivity Enhancement of Surface Plasmon Resonance Sensors with Graphene

The use of graphene in surface plasmon resonance sensors, covering a metallic (plasmonic) film, has a number of demonstrated advantages, such as protecting the film against corrosion/oxidation and facilitating the introduction of functional groups for selective sensing. Recently, a number of works have claimed that few-layer graphene can also increase the sensitivity of the sensor. However, graphene was treated as an isotropic thin film, with an out-of-plane refractive index that is identical to the in-plane index. Here, we critically examine the role of single and few layers of graphene in the sensitivity enhancement of surface plasmon resonance sensors. Graphene is introduced over the metallic film via three different descriptions: as an atomic-thick two-dimensional sheet, as a thin effective isotropic material (same conductivity in the three coordinate directions), and as an non-isotropic layer (different conductivity in the perpendicular direction to the two-dimensional plane). We find that only the isotropic layer model, which is known to be incorrect for the optical modeling of graphene, provides sizable sensitivity increases, while the other, more accurate, models lead to a negligible contribution to the sensitivity.

The era of nano-bionic: 2D materials for wearable and implantable body sensors

Nano-bionics have the potential of revolutionizing modern medicine. Among nano-bionic devices, body sensors allow to monitor in real-time the health of patients, to achieve personalized medicine, and even to restore or enhance human functions. The advent of two-dimensional (2D) materials is facilitating the manufacturing of miniaturized and ultrathin bioelectronics, that can be easily integrated in the human body. Their unique electronic properties allow to efficiently transduce physical and chemical stimuli into electric current. Their flexibility and nanometric thickness facilitate the adaption and adhesion to human body. The low opacity permits to obtain transparent devices. The good cellular adhesion and reduced cytotoxicity are advantageous for the integration of the devices in vivo. Herein we review the latest and more significant examples of 2D material-based sensors for health monitoring, describing their architectures, sensing mechanisms, advantages and, as well, the challenges and drawbacks that hampers their translation into commercial clinical devices.

A Fast and Label-Free Potentiometric Method for Direct Detection of Glutamine with Silicon Nanowire Biosensors

In this paper, a potentiometric method is used for monitoring the concentration of glutamine in the bioprocess by employing silicon nanowire biosensors. Just one hydrolyzation reaction was used, which is much more convenient compared with the two-stage reactions in the published papers. For the silicon nanowire biosensor, the Al2O3 sensing layer provides a highly sensitive to solution-pH, which has near-Nernstian sensitivity. The sensitive region to detect glutamine is from ≤40 μM to 20 mM. The Sigmoidal function was used to model the pH-signal variation versus the glutamine concentration. Compared with the amperometric methods, a consistent result from different devices could be directly obtained. It is a fast and direct method achieved with our real-time setup. Also, it is a label-free method because just the pH variation of the solution is monitored. The obtained results show the feasibility of the potentiometric method for monitoring the glutamine concentrations in fermentation processes. Our approach in this paper can be applied to various analytes.

Cerium functionalized graphene nano-structures and their applications; A review

Graphene-based nanomaterials with remarkable properties, such as good biocompatibility, strong mechanical strength, and outstanding electrical conductivity, have dramatically shown excellent potential in various applications. Increasing surface area and porosity percentage, improvement of adsorption capacities, reduction of adsorption energy barrier, and also prevention of agglomeration of graphene layers are the main advantages of functionalized graphene nanocomposites. On the other hand, Cerium nanostructures with remarkable properties have received a great deal of attention in a wide range of fields; however, in some cases low conductivity limits their application in different applications. Therefore, the combination of cerium structures and graphene networks has been widely invesitaged to improve properties of the composite. In order to have a comprehensive information of these nanonetworks, this research reviews the recent developments in cerium functionalized graphene derivatives (graphene oxide (GO), reduced graphene oxide (RGO), and graphene quantum dot (GQD) and their industrial applications. The applications of functionalized graphene derivatives have also been successfully summarized. This systematic review study of graphene networks decorated with different structure of Cerium have potential to pave the way for scientific research not only in field of material science but also in fluorescent sensing, electrochemical sensing, supercapacitors, and catalyst as a new candidate.

Properties and Applications of Graphene and Its Derivatives in Biosensors for Cancer Detection: A Comprehensive Review

Cancer is one of the deadliest diseases worldwide, and there is a critical need for diagnostic platforms for applications in early cancer detection. The diagnosis of cancer can be made by identifying abnormal cell characteristics such as functional changes, a number of vital proteins in the body, abnormal genetic mutations and structural changes, and so on. Identifying biomarker candidates such as DNA, RNA, mRNA, aptamers, metabolomic biomolecules, enzymes, and proteins is one of the most important challenges. In order to eliminate such challenges, emerging biomarkers can be identified by designing a suitable biosensor. One of the most powerful technologies in development is biosensor technology based on nanostructures. Recently, graphene and its derivatives have been used for diverse diagnostic and therapeutic approaches. Graphene-based biosensors have exhibited significant performance with excellent sensitivity, selectivity, stability, and a wide detection range. In this review, the principle of technology, advances, and challenges in graphene-based biosensors such as field-effect transistors (FET), fluorescence sensors, SPR biosensors, and electrochemical biosensors to detect different cancer cells is systematically discussed. Additionally, we provide an outlook on the properties, applications, and challenges of graphene and its derivatives, such as Graphene Oxide (GO), Reduced Graphene Oxide (RGO), and Graphene Quantum Dots (GQDs), in early cancer detection by nanobiosensors.

A Review on Flexible Electrochemical Biosensors to Monitor Alcohol in Sweat

The continued focus on improving the quality of human life has encouraged the development of increasingly efficient, durable, and cost-effective products in healthcare. Over the last decade, there has been substantial development in the field of technical and interactive textiles that combine expertise in electronics, biology, chemistry, and physics. Most recently, the creation of textile biosensors capable of quantifying biometric data in biological fluids is being studied, to detect a specific disease or the physical condition of an individual. The ultimate goal is to provide access to medical diagnosis anytime and anywhere. Presently, alcohol is considered the most commonly used addictive substance worldwide, being one of the main causes of death in road accidents. Thus, it is important to think of solutions capable of minimizing this public health problem. Alcohol biosensors constitute an excellent tool to aid at improving road safety. Hence, this review explores concepts about alcohol biomarkers, the composition of human sweat and the correlation between alcohol and blood. Different components and requirements of a biosensor are reviewed, along with the electrochemical techniques to evaluate its performance, in addition to construction techniques of textile-based biosensors. Special attention is given to the determination of biomarkers that must be low cost and fast, so the use of biomimetic materials to recognize and detect the target analyte is turning into an attractive option to improve electrochemical behavior.

Rational design of smart nano-platforms based on antifouling-nanomaterials toward multifunctional bioanalysis

The ability to design nanoprobe devices with the capability of quantitative/qualitative operation in complex media will probably underpin the main upcoming progress in healthcare research and development. However, the biomolecules abundances in real samples can considerably alter the interface performance, where unwanted adsorption/adhesion can block signal response and significantly decrease the specificity of the assay. Herein, this review firstly offers a brief outline of several significances of fabricating high-sensitivity and low-background interfaces to adjust various targets' behaviors induced via bioactive molecules on the surface. Besides, some important strategies to resist non-specific protein adsorption and cell adhesion, followed by imperative categories of antifouling reagents utilized in the construction of high-performance solid sensory interfaces, are discussed. The next section specifically highlights the various nanocomposite probes based on antifouling-nanomaterials for electrode modification containing carbon nanomaterials, noble metal nanoparticles, magnetic nanoparticles, polymer, and silicon-based materials in terms of nanoparticles, rods, or porous materials through optical or chemical strategies. We specially outline those nanoprobes that are capable of identification in complex media or those using new constructions/methods. Finally, the necessity and requirements for future advances in this emerging field are also presented, followed by opportunities and challenges.

Laser-Induced Graphene-Functionalized Field-Effect Transistor-Based Biosensing: A Potent Candidate for COVID-19 Detection

Speedy and on-time detection of coronavirus disease 2019 (COVID-19) is of high importance to control the pandemic effectively and stop its disastrous consequences. A widely available, reliable, label-free, and rapid test that can recognize tiny amounts of specific biomarkers might be the solution. Nanobiosensors are one of the most attractive candidates for this purpose. Integration of graphene with biosensing devices shifts the performance of these systems to an incomparable level. Between the various arrangements using this wonder material, field-effect transistors (FETs) display a precise detection even in complex samples. The emergence of pioneering biosensors for detecting a wide range of diseases especially COVID-19 created the incentive to prepare a review of the recent graphene-FET biosensing platforms. However, the graphene fabrication and transfer to the surface of the device is an imperative factor for researchers to take into account. Therefore, we also reviewed the common methods of manufacturing graphene for biosensing applications and discuss their advantages and disadvantages. One of the most recent synthesizing techniques - laser-induced graphene (LIG) - is attracting attention owing to its extraordinary benefits which are thoroughly explained in this article. Finally, a conclusion highlighting the current challenges is presented.

DNA-Based Biosensors for the Biochemical Analysis: A Review

In recent years, DNA-based biosensors have shown great potential as the candidate of the next generation biomedical detection device due to their robust chemical properties and customizable biosensing functions. Compared with the conventional biosensors, the DNA-based biosensors have advantages such as wider detection targets, more durable lifetime, and lower production cost. Additionally, the ingenious DNA structures can control the signal conduction near the biosensor surface, which could significantly improve the performance of biosensors. In order to show a big picture of the DNA biosensor's advantages, this article reviews the background knowledge and recent advances of DNA-based biosensors, including the functional DNA strands-based biosensors, DNA hybridization-based biosensors, and DNA templated biosensors. Then, the challenges and future directions of DNA-based biosensors are discussed and proposed.

Progress on Optical Fiber Biochemical Sensors Based on Graphene

Graphene, a novel form of the hexagonal honeycomb two-dimensional carbon-based structural material with a zero-band gap and ultra-high specific surface area, has unique optoelectronic capabilities, promising a suitable basis for its application in the field of optical fiber sensing. Graphene optical fiber sensing has also been a hotspot in cross-research in biology, materials, medicine, and micro-nano devices in recent years, owing to prospective benefits, such as high sensitivity, small size, and strong anti-electromagnetic interference capability and so on. Here, the progress of optical fiber biochemical sensors based on graphene is reviewed. The fabrication of graphene materials and the sensing mechanism of the graphene-based optical fiber sensor are described. The typical research works of graphene-based optical fiber biochemical sensor, such as long-period fiber grating, Bragg fiber grating, no-core fiber and photonic crystal fiber are introduced, respectively. Finally, prospects for graphene-based optical fiber biochemical sensing technology will also be covered, which will provide an important reference for the development of graphene-based optical fiber biochemical sensors.

An electronic biosensor based on semiconducting tetrazine polymer immobilizing matrix coated on rGO for carcinoembryonic antigen

Point-of-care devices are expected to play very critical roles in early diagnosis and better treatment of cancer. Here, we report the end-to-end development of novel and portable biosensors for detecting carcinoembryonic antigen (CEA), a cancer biomarker, almost instantly at room temperature. The device uses reduced graphene oxide (rGO) as the base conducting layer and a novel poly[(1,4-phenylene)-alt-(3,6-(1,2,4,5-tetrazine)/3,6-(1,2,4,5-dihydrotetrazine))] (PhPTz) as an immobilizing matrix for the CEA antibodies. Judiciously introduced nitrogen-rich semiconducting PhPTz brings multiple advantages to the device—(1) efficiently immobilizes anti-CEA via synergistic H-bonding with peptide and N-glycal units and (2) transports the charge density variations, originated upon antibody-antigen interactions, to the rGO layer. The CEA was dropped onto the anti-CEA/PhPTz/rGO devices at ambient conditions, to facilitate binding and the change in current flowing through the sensors was measured. A response of 2.75–33.7 μA was observed when the devices were tested for a broad range of concentrations (0.25 pg/mL to 800 ng/mL) of CEA. A portable read-out circuit was assembled using Arduino UNO and a voltage divider circuit, and a simple algorithm was developed for the classification of the CEA concentrations. The prediction accuracy of the interfacing electronics along with the algorithm was found to be 100%.

A Review on the Applications of Graphene in Mechanical Transduction

A pressing need to develop low-cost, environmentally friendly, and sensitive sensors has arisen with the advent of the always-connected paradigm of the internet-of-things (IoT). In particular, mechanical sensors have been widely studied in recent years for applications ranging from health monitoring, through mechanical biosignals, to structure integrity analysis. On the other hand, innovative ways to implement mechanical actuation have also been the focus of intense research in an attempt to close the circle of human-machine interaction, and move toward applications in flexible electronics. Due to its potential scalability, disposability, and outstanding properties, graphene has been thoroughly studied in the field of mechanical transduction. The applications of graphene in mechanical transduction are reviewed here. An overview of sensor and actuator applications is provided, covering different transduction mechanisms such as piezoresistivity, capacitive sensing, optically interrogated displacement, piezoelectricity, triboelectricity, electrostatic actuation, chemomechanical and thermomechanical actuation, as well as thermoacoustic emission. A critical review of the main approaches is presented within the scope of a wider discussion on the future of this so-called wonder material in the field of mechanical transduction.

Graphene Based Nanohybrid Aptasensors in Environmental Monitoring: Concepts, Design and Future Outlook

In view of ever-increasing environmental pollution, there is an immediate requirement to promote cheap, multiplexed, sensitive and fast biosensing systems to monitor these pollutants or contaminants. Aptamers have shown numerous advantages in being used as molecular recognition elements in various biosensing devices. Graphene and graphene-based materials/nanohybrids combined with several detection methods exhibit great potential owing to their exceptional optical, electronic and physicochemical properties which can be employed extensively to monitor environmental contaminants. For environmental monitoring applications, aptamers have been successfully combined with graphene-based nanohybrids to produce a wide range of innovative methodologies. Aptamers are immobilized at the surface of graphene based nanohybrids via covalent and non-covalent strategies. This review highlights the design, working principle, recent developmental advances and applications of graphene based nanohybrid aptasensors (GNH-Apts) (since January 2014 to September 2021) with a special emphasis on two major signal-transduction methods, i.e., optical and electrochemical for the monitoring of pesticides, heavy metals, bacteria, antibiotics, and organic compounds from different environmental samples (e.g., water, soil and related). Lastly, the challenges confronted by scientists and the possible future outlook have also been addressed. It is expected that high-performance graphene-based nanohybrid aptasensors would find broad applications in the field of environmental monitoring.

Influence of doping with selected organic molecules on the magnetic and electronic properties of bare, surface terminated and defect patterned Ti2C MXene monolayers

In this study, based on density functional theory, we examine the interaction between the bare, F-, OH-terminated as well as defect patterned Ti₂C and selected neurotransmitter (NT) and amino acids (AA) such as dopamine, glutamate, glycine and serine. We found that these molecules are dissociated at a specific location in bare Ti₂C monolayers and concomitantly they form Ti-H bonds. The adsorbed molecules give rise to significant charge transfer between the adsorbates and underlying substrates and generally the electronic energy states are affected, band gaps are tuned and magnetic moments are attained significantly. In particular, the bare antiferromagnetic-Ti₂C monolayer undergoes an antiferromagnetic-ferromagnetic transition upon adsorption of the amino acids and nucleobase molecules due to bond dissociation of molecules. Moreover, the electronic and magnetic properties of bare Ti₂C are crucially changed in the presence of a vacancy. While pristine Ti₂C is an AFM semiconductor, mono- and di-vacancy structures become ferromagnetic semiconductors. When adsorbed by molecules, the defect patterned Ti₂C is spin-polarized and hence the surface results in a metallic state. We also reveal that the Ti₂C structure is transformed to the non-magnetic (NM) ground state in the presence of both F- and OH-surface termination groups. When adsorbed to these organic molecules on a terminated Ti₂C surface, the binding of molecules to this surface is generally weak and arises from van der Waals interactions. We determine that the binding energy of dopamine, which is absorbed on bare Ti₂C in equilibrium in a solvent, was found to be 2.31 eV and the magnetic moment per supercell was reduced to 2.91μ_B.